THE EFFECT OF FOOD-DEPRIVATION ON THE INNATE VISUAL AND OLFACTORY PREFERENCES IN THE PARASITOID COTESIA-RUBECULA

The response of Cotesia rubecula (Hymenoptera: Braconidae) to olfactory and visual flower stimuli was tested. It was demonstrated that parasitoids can use both flower-odors and -colors during food foraging. The response of parasitoids to food-indicating stimuli depended on the hunger state of the individual. Given a choice in a Y-tube olfactometer between flower odors and odors from host-infested leaves, food-deprived individuals chose flower odors, while sugar-fed individuals preferred host associated odors. In flight chamber experiments, food-deprived parasitoids landed more often and spent more time searching on yellow targets, while sugar-fed individuals displayed a higher overall foraging activity, without reacting differentially to yellow.